Similar immunity profiles in patients with meningioma and glioma tumors despite differences in the apoptosis and necrosis of circulating lymphocyte and monocyte populations.

AIM: The present study aims to compare the host immune responses induced by benign (meningiomas) and malignant (gliomas) brain tumors.

METHODS: Peripheral blood samples from 8 meningioma and 7 glioma patients collected pre- and post operatively were assessed for cell-mediated immunity, humoral immunity and IL-6, IL-8 and TNF-a expression. Apoptosis and necrosis of circulating lymphocytes and monocytes were evaluated by Annexin/PI, while DNA analysis was applied to trace circulating cells with an abnormal DNA content.

RESULTS: Cell-mediated immunity was similar in the two groups either pre- or post- operatively. However, differences in the apoptosis and necrosis of circulating lymphocytes and monocytes were observed. Menigioma patients were characterized by increased percentage of apoptotic lymphocytes and necrotic monocytes pre-operatively and apoptotic monocytes postoperatively. In contrast glioma patients showed an increase in necrotic monocytes postoperatively. Humoral immunity and cytokine expression were at comparable levels both pre- and post-operatively. IL-6 expression was significant elevated after surgery in both groups. Circulating aneuploid cells were identified in three glioma patients pre-operatively, by DNA analysis.

CONCLUSION: The presented data indicate that meningioma and glioma tumors trigger comparable systemic host immunity response mediated by impairments in cell-mediated immunity due to alternations in apoptosis and necrosis that also influence their shift towards the Th2 immunity profile. Moreover, the presented evidences on the circulation of aneuploid cells in glioma patients may substantiate further the immunosuppressive phenotype detected in these patients and offer a mechanism for the rare cases that extra- neural dissemination was observed without previous surgical intervention.